How to fix Cisco VPN Client error 442 on Windows Vista???

Everyone has dealed with Cisco VPN Client on Vista probably knows the notorious Error 442 – Failed to enable virtual adapter. AFAIK this is a bug from Cisco that stays unfixed for at least 5 months (from the version 5.0.00.0340 released on May 2007 until now). Whether it is Cisco or Microsoft to point the finger at, i really don’t know.

So … you probably already tried this work-around suggestion from Cisco’s release notes:

Run cmd as Administrator and execute the following command:
reg add HKLM\System\CurrentControlSet\Services\Tcpip\Parameters /v ArpRetryCount /t REG_DWORD /d 0 /f

It just does not work ( at least every time i faced Error 442 ). What you should do is:

•Remove the client
•Activate the real Administrator account ( for detailed howto see this post )
•Restart, then log into the administrator account
•Install the file as normal ( right-click on it, choose “Run as Administrator”)
•After the installation finishes, restart again.
The client should work now. If not try to remove the Deterministic Network Enhancer protocol first, then reinstall VPN. Have patience, you will need to restart your computer sometimes.

Some people say the removal of Microsoft SQL do the trick (strange, erh ?), or simply turn on Media Sharing in the Network and Sharing Center. I haven’t tried this, so if it fixes your problem, then good for you.

If you could post your result here, then i am very appreciated